Wearable computer in a process control environment

ABSTRACT

A wearable computer for use in a process control environment includes a central processing unit, a memory and a number of other or integral devices such as a display, a microphone, a video camera, a voice recognition unit and a remote communication device that communicates with a host computer. The wearable computer provide information pertaining to one or more devices within a process control system (such as diagnostic information, help information, operator overviews, schematics or process parameter information) via the display. The wearable computer also executes a voice recognition routine that processes a received voice signal to automatically identify user inputs such as commands, process control devices within the field of view of the wearer, device tags, etc. and uses the user inputs to change a display, to alter a process signal, to retrieve device information etc.

This application is a divisional of U.S. Ser. No. 09/249,597 entitled“Wearable Computer in a Process Control System,” which was filed on Feb.12, 1999. This application is also a continuation of U.S. Ser. No.11/010,016 entitled “Wireless Hand Held Communicator in a ProcessControl Environment,” which was filed on Dec. 10, 2004, which is acontinuation in part of U.S. Ser. No. 10/936,978 entitled “PortableComputer in a Process Control System,” which was filed on Sep. 9, 2004,which is a continuation of U.S. Ser. No. 09/951,715 entitled “PortableComputer in a Process Control System,” which was filed on Sep. 13, 2001and which issued as U.S. Pat. No. 6,806,847 on Oct. 19, 2004, which is acontinuation-in-part of U.S. Ser. No. 09/249,597 entitled “WearableComputer in a Process Control System,” which was filed on Feb. 12, 1999,the entire disclosure of each of which is hereby expressly incorporatedby reference herein.

FIELD OF TECHNOLOGY

The present invention relates generally to process control systems and,more particularly, to the use of a wearable computer to provide enhancedsupport within a process control environment.

DESCRIPTION OF THE RELATED ART

Process control systems, like those used in chemical, petroleum or otherprocesses, generally include a centralized process controller that iscommunicatively coupled to at least one host or operator workstation andto one or more field devices via analog, digital or combinedanalog/digital buses. The field devices, which may be, for examplevalves, valve positioners, switches, sensors (e.g., temperature,pressure and flow rate sensors), etc., perform control functions withinthe process such as opening or closing valves and taking measurements ofprocess parameters. Generally speaking, the process controller receivessignals indicative of process measurements made by the field devicesand/or other information pertaining to the field devices, uses thisinformation to implement a control routine and then generates controlsignals which are sent over the buses to the field devices to controlthe operation of the process. Information from the field devices and thecontroller is typically made available to one or more applications thatare executed by the operator workstation to enable an operator toperform any desired function with respect to the process, such asviewing the current state of the process, modifying the operation of theprocess, etc.

While an operator or a technician can access a variety of types ofinformation pertaining to the process control system and the individualdevices therein (such as help, diagnostic, set-up and configurationinformation) using the host workstation, there are many process controlactivities that require a technician to go out into the actual plantenvironment where no host workstation is present. Such activitiesinclude, for example, visually inspecting a process control device orarea, connecting devices or buses within the process controlenvironment, taking manual measurements, repairing and replacing fielddevices, etc. In these cases, the operator or technician may carrymanuals pertaining to the function to be performed out into the plantand look up any needed information in the field. This process can bevery cumbersome. More likely, the technician will return to the operatorworkstation one or more times to look up any information he or she mayneed during the course of the performing the desired activity, which isvery time consuming and is prone to error. Other times, the technicianwill carry a radio or walkie-talkie into the plant and communicate viathe radio with an operator located at the operator workstation to getany needed information. However, the amount of information that can beprovided over the radio is limited and, again, is prone to errorsbecause it is based on human communications. Furthermore, because thetechnician typically carries and operates the radio using his or herhands, the use of a radio makes performing certain functions, likerepairing a device, much more cumbersome and difficult.

With the advent of smaller electronics, portable computers in the formof wearable computers have become more readily available. A wearablecomputer generally includes a standard central processing unit (CPU) anda memory packaged in a small container and placed within a pouch on abelt or harness worn by a user (also referred to herein as a “wearer”).Batteries for powering the wearable computer are typically located in adifferent pouch within the harness, which is designed to make carryingthe wearable computer as convenient as possible. Peripheral devices,such as disk drives, hard drives, PCMCIA slots, microphones, bar codereaders and keyboard devices may be communicatively coupled to the CPUvia appropriate wires or buses and, if desired, one or more of theseperipheral devices may be placed in of connected to the harness. It hasalso been suggested to provide a heads up display (HUD) worn by thewearable computer user to present the wearer with a visual interface. Awearable computer thereby provides portable computing power and memoryto a user and, because the wearable computer is worn instead of carriedby the user, the user's hands are only required to manipulate a keyboardor other input device.

While it has been previously suggested to use wearable computers inenvironments such as office environments, it is not believed that awearable computer has been incorporated in and used in a process controlsystem to enhance the abilities of an operator or a technician toidentify devices and to perform other functions within a process controlenvironment. Also, most wearable computers require the use of some sortof hand-manipulated input device, such as a keyboard or a twiddler.While these devices are typically ergonomically designed to be as leastcumbersome as possible, these devices still require the use of a thewearer's hands to input information or data. In a process controlenvironment however, a technician typically needs to have both handsfree in order to perform complex operations, such as calibrating andrepairing devices, connecting devices within the process control system,etc.

SUMMARY

A wearable computer for use in a process control environment includes acentral processing unit and a memory connected to one or more peripheraldevices including, for example, a heads up display, a microphone, animaging device (such as a video camera) and a remote communicationdevice (such as a wireless ethernet transceiver) that communicates witha host computer of a process control system. The wearable computer mayprovide information pertaining to one or more devices within the processcontrol system via the heads up display. The information which can be,for example, diagnostic information, help, operator overviews,schematics or process parameter information, may be stored in the memoryof the wearable computer or may be obtained from the host computer viathe remote communication device.

The wearable computer may include a software routine or asoftware/hardware device that processes an image developed by theimaging device to automatically identify process control devices withinthe field of view of the wearer based on device features. Thisprocessing, which can performed on the basis of device tags required tobe placed on devices within process control environments, automaticallyidentifies one or more process control devices without requiring theuser to input any information via a hand manipulatable device and may beused to provide the wearer with information pertaining to the identifieddevices, including process parameter values developed by the identifieddevices.

Still further, the wearable computer can be used to test the properconnection of devices and/or communication channels within the processcontrol system. In this embodiment, a software routine run on thewearable computer displays information to the wearer via the HUDincluding, for example, a list of devices or communication channels, andallows the wearer to select an appropriate device and/or communicationchannel to be tested. The wearer may choose a device or channel usingverbal commands decoded by a voice recognition routine run on thewearable computer or using commands entered via any other input device.After the appropriate I/O channel has been chosen, the routine obtainsthe current value of the signal on the selected channel via remotecommunications with the host computer and displays this value to thewearer on the HUD. At this point, the wearer can manually test the valueon the actual communication channel using, for example, a hand-heldmeasurement device. The routine then allows the wearer to change thevalue of the channel by inputting a new value using, for example, voicecommands. Next, the routine communicates the new value to the hostcomputer, which changes that value within the process control system andcommunicates the change back to the wearable computer. The change may bedisplayed to the wearer via the HUD, at which point the wearer may againmanually measure the signal on the channel to see if the measured signalhas changed to the new value. If not, a problem exists within theprocess control system configuration. Using this system, the wearer cantest the connections within a process control environment in a handsfree manner and without having to communicate changes to be made toanother person located at a different part of the plant (e.g., at anoperator workstation).

In another embodiment, routines run on the wearable computer and a hostworkstation enable the wearer and an operator at the host workstation toview and manipulate a common image to thereby enhance communicationsbetween the operator and the wearer. The host system may receive a videosignal developed by the video camera of the wearable computer and mayselect a base image for shared viewing. This image is displayed on thehost display and is sent to the wearable computer to be displayed on theHUD. Thereafter, one or both of the operator and the wearer maymanipulate the image by, for example, moving a cursor within the image,highlighting, placing data or information on the image, etc. and suchchanges are sent to the other system so as to be displayed on both thehost display and the HUD.

In a still further embodiment, the wearable computer may be used tocreate and store information, for example, in the form of voicemessages, pertaining to any device or other object within the processcontrol environment. Such information may then be automatically suppliedto any wearer or operator who later passes by the device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic block diagram of a process control network havinga wearable computer system remotely coupled thereto;

FIG. 2 is a schematic block diagram of the wearable computer system ofFIG. 1;

FIG. 3 is a flow chart diagram of a software routine that processesvoice data to recognize commands in the wearable computer system of FIG.2;

FIG. 4 is a flow chart diagram of a software routine that automaticallyrecognizes process control devices based on video information collectedby the wearable computer system of FIG. 2;

FIG. 5 is a flow chart diagram of a set of software routines thatprovide a shared image between a host system and the wearable computersystem of FIG. 2;

FIG. 6 is a flow chart diagram of a software routine that providessupport to a wearable computer user who is verifying communicationconnections within a process control environment;

FIG. 7 is a first wearable computer screen display used in the softwareroutine of FIG. 6;

FIG. 8 is a second wearable computer screen display used it the softwareroutine of FIG. 6; and

FIG. 9 is another wearable computer screen display used in the softwareroutine of FIG. 6.

DETAILED DESCRIPTION

Referring now to FIG. 1, a process control system 10 includes a processcontroller 12 connected to a host workstation or computer 14 (which maybe any type of personal computer or workstation) and to field devices15, 16, 17, 18, and 19 via input/output (I/O) cards 20 and 22. Thecontroller 12, which can be by way of example, the DeltaV™ controllersold by Fisher-Rosemount Systems, Inc., may be communicatively connectedto the host computer 14 via, for example, an ethernet connection and maybe communicatively connected to the field devices 15-19 using hardwareand software associated with any desired communication protocol, such asthe FOUNDATION™ Fieldbus, the HART®, PROFIBUS®, WORLDFIP®, Device-Net®or CAN protocols, to name a few. As is typical, the controller 12implements a process control routine stored therein and communicateswith the devices 15-22 and the host computer 14 to control a process inany desired manner. The field devices 15-19 may be any type of devices,such as sensors, valves, transmitters, positioners, etc. while the I/Ocards 20 and 22 may be any types of I/O devices conforming to anydesired communication or controller protocol.

As illustrated in FIG. 1, the host computer 14 is communicativelycoupled to a wearable computer system 30 through a remote or wirelesscommunication device, such as a remote ethernet transceiver 32.Alternatively, the host computer 14 may be coupled to the wearablecomputer system 30 via a physical line or bus having terminals locatedthroughout the process control environment to which the wearablecomputer system 30 can be temporarily connected and disconnected.

The wearable computer system 30 includes a wearable computer 34 having aremote transceiver 36 and a number of peripheral devices attachedthereto. In the preferred embodiment, the wearable computer 34 includesa Pentium class CPU mother board with video, sound, RAM (e.g., 64 Mb)and ROM with a hard drive (e.g., 4.3 Gb), all located within a wearablecomputer harness (not shown). The wearable computer 34 may include anynumber of slots, such as PCMCIA slots, one of which can be used toreceive the remote transceiver 36 and another of which may be used toreceive a video processing board such as a video frame capture board.The peripherals communicatively coupled to the wearable computer 34include an imaging device 38, which may be a video camera, a HUD 40, aspeaker 42 (which may be a headphone speaker or any other type ofspeaker), a microphone 44 and a user input device 46 which may be forexample, a typical keyboard, a mouse, a track ball, or a twiddler devicehaving a limited number of easy to use keys (such as function keys), thefunction of which is defined differently for different applications. Ofcourse, any other peripheral devices may be used in addition or in thealternative.

While the imaging device 38 is preferably a video camera, it may insteadbe any other type of imaging device, such as a digital camera, that iscompact and easily transported by the wearer in a hands-free manner.Most preferably, the video camera 38 or other imaging device is mountedon the HUD 40 or on some other device (such as wearable headgear) whichpoints in the direction that the wearer is looking. One small and easilymounted video camera that can be used for this purpose is sold by thePulnix corporation. This video camera conforms to the high definitiontelevision (HDTV) standard (i.e., produces an 800 by 600 color pixelimage frame), has about one quarter of an inch to one half of an inchdiameter lens and produces a high resolution color image. However, othervideo cameras can be used instead including, for example, video camerasthat produce high or low definition color or black and white (i.e.,gray-scale) images. In some instances, a low definition video camera(either color or black and white) may be preferable to speed up the timeneeded to process an image in the manner described below.

The HUD 40 may use an NTSC video format and is preferably a monocularHUD such as the M1 HUD sold by Liquide Image Corp. located in Canada.This HUD provides a quarter VGA (i.e., 320 by 240 pixel) gray-scaleimage. Of course, HDTV format HUDs (which are currently prohibitivelyexpensive) or other color or gray-scale HUDs, either those available nowor those developed in the future, could be used instead. The speaker 42,the microphone 44 and the input device 46 can be any suitable and easilytransportable devices preferably mounted with respect to the wearer in ahands-free manner. In one embodiment, a bone microphone may operate asboth the microphone 44 and the speaker 42. As is known, bone microphonesuse the bones within the wearer's jaw to detect voice signals and/or toproduce sound signals at the wearer's ear.

With the wearable computer system 30 installed, the wearer still hasboth hands free to perform other activities, such as repairing devices,taking measurements or holding other instruments. Of course, the inputdevice 46 may require one or both hands to operate, but is stillpreferably mounted in a hands-free manner with respect to the wearer.

Referring now to FIG. 2, the wearable computer 34 includes a CPU 50coupled to a memory 52, which may be any type of memory including, forexample, a disk drive (such as a hard, magnetic or laser disk storagedevice), RAM, ROM, EEPROM, EPROM, etc. The CPU 50, which can include oneor any multiple number of processor units (or other hardwired orfirmware elements) operating independently or in a coordinated manner,executes one or more software applications (stored in the memory 52)using any of the inputs to the wearable computer 34, information storedin the memory 52 and/or information provided from the host system viathe transceiver 36. The CPU 50 also provides outputs to the peripheraldevices, as well as to the host system via the remote communicationdevice, i.e., the transceiver 36. In the embodiment of FIG. 2, the CPU50 is illustrated as including a controller 54 which (may be implementedin hardware or software) and which executes the operating systemassociated with the wearable computer 34 to recognize different inputsfrom the peripheral devices and other components of the wearablecomputer 34 and to execute one or more applications. The CPU 50illustrated in FIG. 2 includes or executes a voice recognition unit 56,an optical character recognition (OCR) unit 60, a speaker driver 62 anda HUD driver 64. Furthermore, the CPU 50 is coupled to a video framegrabber 68 which may be provided on a separate video processing board.

The voice recognition unit 56 which may be, for example, the DragonDictate system sold by Dragon Systems of Boston, Mass., or any otherdesired voice recognition unit, is typically implemented in software butmay, alternatively, be executed on a separate processor board. In anyevent, the voice recognition unit 56 receives speech, voice or othersound signals from the microphone 44, performs voice recognitionprocessing thereon and delivers commands to the controller 54 based onrecognized voice inputs. The voice recognition unit 56 may perform anydesired or known processing on the received voice signals to identifycertain recognized speech commands or words. During this process, thevoice recognition unit 56 may compare an identified voice command to alist of stored or recognized speech commands (stored in, for example,the memory 52) to determine if a valid command is being delivered by thewearer. If a recognized command has been received, the voice recognitionunit 56 delivers the command to the controller 54 for furtherprocessing. Of course, if desired, the controller 54 may determine if avoice command is a valid or recognized command within the context of theapplication being run on the controller 54 and may notify the user whenin unrecognized command is received. The voice recognition unit 56 mayalso have learning capabilities, as is known.

FIG. 3 illustrates a block diagram of a software routine 80 thatprocesses a voice signal to identify voice commands and which may beexecuted by the wearable computer system 30 to enable the wearer toenter data or commands verbally and, therefore, in a hands-free manner.A block 82 of the routine 80 receives a voice signal from the microphone44. A block 84 processes the voice signal to identify a voice commandwithin the signal using any desired or standard voice recognitionprocessing routine, such as that indicated above. A block 86 thencompares the identified command or input with a set of commands storedin, for example, the memory 52, to determine if the command is valid. Ifa block 68 determines that the voice command is recognized, a block 90provides the command to the controller 54 to be used by whateverapplication is expecting such command. Thereafter, or if the voicecommand signal is not recognized as a valid command at the block 88,control is returned to the block 82 which receives and processes furthervoice signals. Of course, if an invalid command has been received, theroutine 80 may display an indication of such to the wearer.

The video processing unit provided within the wearable computer 34 ofFIG. 2 includes the frame grabber 68 coupled to the OCR unit 60 butcould include other video or image processing hardware/software as well.The frame grabber 68 may be, for example, a Nogatek board sold by theNogatek Company, while the OCR unit 60 may be, for example, the Carinareal-time OCR package which is sold by Adaptive Recognition Hungary,located in Budapest, Hungary. While this particular OCR unit haspreviously been used to identify license plate numbers on vehicles, itis believed that this product or a derivative of this product (havingonly minor modifications thereto) would operate satisfactorily torecognize device features as described below. Of course, other suitableframe grabber boards and OCR packages could be used as well. Asillustrated in FIG. 2, the frame grabber 68 receives an image signal(having multiple image frames therein) from the video camera 38 andprovides an output frame to the OCR unit 60. (Of course, if the imagingdevice 38 produces a still image, such as that produced by a digitalcamera, the frame grabber 68 may be unnecessary.)

In one embodiment, the OCR unit 60 processes the received image toidentify device features within the image, and these device features arethen used to identify one or more devices within the field of view ofthe video camera 38. For example, the OCR unit 60 may look for andrecognize predetermined symbols, such as alpha-numeric symbols locatedon field devices, and provide such recognized symbols to the controller54 for device identification. Of course, if desired, the output of thevideo camera 38 may be used for other purposes. For example, the videoimage may be provided to the controller 54 to be displayed on the HUD 40and/or may be sent to the host computer 14 via the transceiver 36 forviewing or and/or processing by the host computer 14.

Referring to FIG. 4, a routine 100 illustrated in flow chart form may beimplemented in software executed by the wearable computer 34 toautomatically recognize devices within the field of view of the wearerbased on the video input collected by the imaging device 38. A block 102obtains a video or other image from the imaging device 38. If theimaging device 38 is a video camera, the block 102 may use the framegrabber 68 to grab a particular video frame. However, if the imagingdevice is, for example, a digital camera, the block 102 may access theimage directly without the aid of the frame grabber 68.

A block 104 then processes the obtained video image or frame to identifypotential device features within the video frame. In one embodiment, thedevice feature is a device tag mandated to be placed on each of thefield devices within a process control environment by OSHA. Usually,such device tags include a rectangular holder or frame (typically one totwo inches high by three to four inches wide) having alpha-numericcharacters etched or otherwise engraved or carved therein so as to bevisible to persons within the process environment. The alpha-numericcharacters are usually a different color than the frame to make thesecharacters more visible. When recognizing device tags, the block 104scans the image to identify areas likely to contain device tags, such asrectangular areas within the image, areas with certain ranges of colors,areas having alpha-numeric characters therein, etc. Of course anydesired processing may be used to search for these device features.Thereafter, a block 106 recognizes or decodes the device features withinthe identified areas. In particular, when device tags are beingidentified, the block 106 may apply optical character recognition (usingthe OCR 60) on the identified features to produce a preliminary deviceID. If more than one device is within the image being processed, theblocks 104 and 106 may recognize numerous device features (such asdevice tags) and identify numerous preliminary device IDs.

Next, a block 108 compares each of the preliminary device IDs to a listof device IDs stored in, for example, the memory 52 to verify theexistence of devices corresponding to the preliminary device IDs. If coresponding devices exist, the device IDs are verified and each of theverified IDs is provided by a block 110 to the controller 54 for use inother applications, to be displayed to the wearer via the HUD 40 and/orto be sent to the host computer 14 via the transceiver 36.

While the routine 100 can identify devices based on any observablefeatures, it is preferable that the routine 100 identify devices basedon device features, i.e., features that are part of the device as it isplaced in the field without regard to automatic detection andidentification by the wearable computer system 30. In other words, whileit would be possible to place bar codes or other unique identifiers oneach of the devices within a process control environment, it ispreferable to have the routine 100 identify devices based on featuresthat are not placed on the device solely for the purpose of detection bythe wearable computer system 30, i.e., features already existing on thedevice for other purposes. If detection and identification is performedusing device features, then no additional steps need to be taken tolabel or otherwise mark each device within a process control environmentfor the specific purpose of being identified by a wearable computer.

Other applications which, for example, automatically display informationto the wearer via the HUD 40 may display the identified devices to thewearer, may display other information pertaining to the identifieddevice(s) to the wearer via the HUD and/or may send the identifieddevice IDs to the host system 14. Of course, the list of recognizeddevices may be stored in the memory 52 of the wearable computer 34 orwithin a different memory, such as a memory within the host system 14which can be accessed via remote communications by the block 108 toverify preliminary device IDS. As will be understood, it is notessential that each of the blocks of the routine 100 be executed withinthe wearable computer system 30. Instead, one or more of these blockscan be executed by the host computer 14, which can communicate with thewearable computer system 30 to perform the routine 100.

Referring again to FIG. 2, the speaker driver 62 takes signals providedby the controller 54 and processes them by, for example, converting themto standard analog audio signals, amplifying them, etc. The speakerdriver 62 then provides the processed signal to the speaker 42. As willbe readily understood, the speaker driver 62 and the controller 54 maybe used to play prerecorded signals stored in, for example, the memory52 or the memory of the host computer 14 and/or may be used to relayreal-time audio produced by or at the host system, such as the voice ofan operator located at the host system, or the voice of another wearablecomputer user located elsewhere within the process control environment.The voice or audio signals to be played on the speaker 42 may beprovided to the wearable computer 34 via the transceiver 36 from thehost system or may be provided using any other audio communicationsystem coupled to the wearable computer 34.

Similarly, the HUD driver 64 receives signals from the controller 54including graphics to be displayed on the HUD 40, and performsappropriate processing on these signals for display via the HUD 40. Insome embodiments, the HUD driver 64 and the HUD 40 may be used inconjunction with the twiddler 46 or microphone 44 to provide a standardcomputer operating environment, such as a Windows image having dialogueboxes, text, graphics and the like. With this environment, the wearercan move a cursor, enter information or manipulate the image on the HUD40 to, for example, run in application or make decisions within thecontext of an application being executed by the wearable computer 34.

The controller 54 uses the transceiver 36 in any desired or standardmanner, and provides signals to the transceiver 36 for communication tothe host system using any desired communication protocol. Likewise, thecontroller 54 receives and decodes communications from the host computer14 via the transceiver 36 using any desired communication protocol.

The wearable computer system 30 of FIG. 2 can be used to providenumerous kinds of information to the wearer and/or to perform functionswithin the process control environment which make the wearer's taskeasier and quicker when the wearer is, for example, inspecting,installing, repairing, calibrating and checking the connections ofdifferent devices within the process control environment. For example,using the wearable computer system 30, a wearer can obtain and viewinformation pertaining to certain devices or areas within the processcontrol environment via the HUD 40 either automatically or afterappropriate input via one of the peripherals. The wearable computer 34may store, or may communicate with the host computer 14 to obtain, anydesired information pertaining to a particular device or to the processcontrol system in general and display that information to the wearer viathe HUD 40 at the request of the wearer or when the wearable computersystem 30 recognizes a device within the field of view of the wearer asdescribed above. The displayed information may include processinformation, such as schematics or operator overviews of the processcontrol system, device information such as device lists, helpinformation, diagnostic information and even process parameterinformation (such as measurements, parameter values, etc.) made by orassociated with one of more of the devices connected within the processcontrol system.

To view such information, the wearer can, when walking by a device,enter a device identifier, such as a device tag or a device number,which may cause the controller 54 to automatically display certain kindsof device information, such as help, calibration, diagnostics, parametervalues, etc. Of course the wearer can enter the device identifier usingthe twiddler 46, the microphone 44 or any other input device. When usingthe microphone 44, the voice recognition unit 56 can identify, forexample, a spoken device tag number or name and provide that device tagnumber or name to the controller 54. If desired, the voice recognitionunit 56 can be set up to receive a device number, a device name or anyother device identifier and compare the entered identifier to a list ofvalid device numbers or names within the memory 52.

In one embodiment, as described above, the devices within the field ofview of the wearer are automatically detected by the video processingcircuitry and, when such detection takes place, information about thedevice may be automatically displayed to the wearer via the HUD 40 inany desired format. If the information is stored in the memory 52, theinformation can be automatically accessed by the controller 54 andprovided or displayed via the HUD 40 using the HUD driver 64.Alternatively, if the information is stored within the host system, thecontroller 54 may request and receive the appropriate information viathe transceiver 36 and then display such information on the HUD 40. Inthe case of process parameters measured by or stored within a device,the host system may communicate with the device to obtain the mostrecent values or data before delivering that information to the wearablecomputer system 30.

In any of these cases, the controller 54 can display a list ofrecognized devices to a user and allow the user to choose to viewinformation about any of the devices or, alternatively, the controller54 can automatically display information about the recognized devicesvia the HUD 40. Significantly, the use of the microphone 44, the videocamera 38 and the associated hardware/software on the wearable computersystem 30 enables the wearer to receive and view information pertainingto devices (or areas or other units of the process control system)automatically in a hands-free manner, i.e., without having to enter anydata or other information via a hand-held or hand manipulated device.This leaves the wearer's hands free to perform other tasks, such asrepairing, replacing or calibrating a device, manipulating other tools,etc. which is very advantageous. Still further, the wearable computersystem 30 can receive and display information measured by or storedwithin devices at which the wearer is actually looking, without the needfor separate dials or displays being physically located on the outsideof each device.

In another embodiment, the wearable computer system 30 can be used toprovide a shared view (e.g., display) to an operator located at, forexample, the host computer 14 and to the wearer via the HUD 40 tothereby enhance communications between the two. Such a shared viewapplication displays the same image to both persons and allows one orboth of these persons to manipulate the image to, for example, point outor highlight particular parts of the image or post data on the image.These actions can be used in conjunction with voice communications tothereby enhance conversations between the wearer and an operator locatedat the host computer 14.

FIG. 5 illustrates a block diagram of a software routine 116 that can berun on the host computer 14 and a block diagram of a software routine118 that can be run on the wearable computer system 30 to implement ashared view or display. The routine 118 includes a block 120 thatcollects and sends a video image to the host computer 14 via thetransceiver 36. (Communications between the wearable computer system 30and the host computer 14 are illustrated in FIG. 5 by dotted lines.)This image may be the entire multi-frame image produced by the videocamera 38 or may be any one or more individual frames thereof. A block122 within the routine 116 receives the video image and a block 124displays the video image to the operator via a display device associatedwith the host computer 14. A block 126 enables the operator at the hostcomputer 14 to choose a frame of the video image to be used as the basisfor the shared view (a base image). The block 126 may, for example,simply display the most recently received frame of the received videosignal and wait for the operator to indicate that a freeze of the imageis requested. Alternatively, the block 126 may allow the operator toreplay received frames to choose a desired image or may allow theoperator to choose a base image in any other desired manner. If theoperator does not choose a base image for the shared display, the block126 provides control back to the block 122. If the operator chooses abase image at the block 126, a block 128 sends the selected base imageto the wearable computer system 30 for display to the wearer on the HUD40. The block 128 may also, if desired, display the selected base imageto the operator via the display of the host computer 14.

Next, a block 130 within the routine 116 determines whether changes tothe base image are being made or requested by the host computeroperator. Such changes may include, for example, moving a cursor or apointer, drawing on the image, highlighting areas of the image, postinginformation or other data on the image, or any other desired changeswhich enable the operator to communicate with the wearer using theimage. These changes may be made by the operator using any desiredoperating system protocols and peripheral devices, such as a mouse and akeyboard. If changes to the image are made by the operator, a block 132sends the changes to the wearable computer system 30 via the transceivernetwork 32/36. The changes may be communicated using any desiredprotocol and either the specific changes being made or an entire newimage frame having the changes therein can be sent to the wearablecomputer system 30, as desired. In one embodiment, changes to the imagein the form of pointer movements may be communicated as new pointercoordinates. After image changes have been made and sent to the wearablecomputer system 30, or if no new changes are made by the host operator,a block 134 refreshes the image of the host system (incorporatingchanges made by the operator as well as changes made by the wearablecomputer system and sent to the host system). Control of the routine 118is then returned to the block 130 to detect other changes made by thehost operator.

Meanwhile, the routine 118 includes a block 136 that displays the baseimage received from the host system on the HUD 40. A block 138 thendetects changes to the image made by the wearer, which changes can bemade using any available input device including the microphone 44 andthe twiddler 46. If the wearer makes changes to the displayed image, ablock 140 sends the changes to the host computer 14. Thereafter, or ifno wearer initiated changes are detected, a block 142 refreshes theimage on the HUD 40 incorporating changes made by the wearer as well aschanges made by and received from the host computer 14. Control of theroutine 118 is then returned to the block 138 for detection of furtherwearer initiated changes.

In this manner, the routines 116 and 118 operate on the host computer 14and on the wearable computer system 30 to provide a shared view or scenethat can be manipulated by one or both of the host operator and thewearer to enhance communications between the two. While the base imagehas been described herein as being derived from an image collected bythe wearable computer system 30, this need not be the case. The baseimage could, instead, be a stored operator view, schematic, etc. relatedto the process or device of interest. In either case, the shared viewenables the host operator to point out and talk about different elementswithin the displayed image in a manner that is easily viewable by thewearer. Furthermore, if desired, the wearer can make changes to theimage using, for example, the same or a different cursor to aidconversations with the host operator. If desired, the wearer need not beable to make changes to the image, which simplifies the routines 116 and118 of FIG. 5. Also, if desired, the wearer may select the base image tobe used before it is sent to the host computer 14.

Another use of the wearable computer system 30 within a process controlenvironment will be described in conjunction with the routine 150,illustrated in flow chart from in FIG. 6, which is preferably executedwithin the wearable computer system 30. Generally speaking, the routine150 enables the wearer to check out and verify the proper connection ofdifferent devices or communication channels (such as I/O connections)within a process control environment in a hands-free manner and withoutthe aid of an operator at a host device. Previously, verifying theproper connections of the devices or communication channels within aprocess control environment required a technician to go out into thefield with a hand-held measurement device, such as a voltmeter, and ahand-held radio which the technician used to communicate with anoperator at a host workstation. The technician first had to go to adevice, indicate to the host operator via the hand-held radio that he orshe was at the device and then indicate which communication channel heor she was going to check. At this point, the technician had to take ahand-held meter and actually measure the signal on the line. Thetechnician then told the host operator, via the hand-held radio, whatthe measured signal was so that the host operator could verify whetherthe measured signal was the actual signal on the selected communicationchannel. Thereafter, the technician would tell the host operator tochange the signal on the channel in question and the host operator wouldcause the signal or value of the communication channel to be changed.The technician would then measure the signal on the channel again to seeif the change actually occurred. As is evident, this process required alot of cumbersome communications between the host operator and atechnician and was difficult to implement in a large and complex processcontrol environment where the technician was trying to simultaneouslymanipulate a hand-held radio, a hand-held meter and obtain access toappropriate devices or communication lines. Furthermore, this processrelied on communications between a host operator and the technicianwhich tended to create confusion and to introduce errors based onmiss-communications.

Using the routine 150 of FIG. 6, a wearer can check out devicecommunication channel connections, such as I/O connections, within aprocess control system in a relatively hands-free manner (i.e., holdingonly a measurement device) and without the need to communicate with anoperator located at a host workstation. Instead, the wearable computersystem 30 communicates directly with the host computer to provide thewearer with all the information he or she needs and to make changesrequested by the wearer necessary to check out the connections of adevice or a communication channel within the process control system.Using the routine 150, the wearer can go out into the process controlenvironment, obtain a list of devices and/or communication channelsassociated with a device, choose a particular device and/orcommunication channel for testing, find out what the signal on thedevice or channel being tested should be, make changes to the signal andmeasure both the original signal and the changed signal to test theproper connection of the device or channel, all without the need for ahost operator.

The routine 150 includes a block 152 that displays a list of devicesthat may be tested on the HUD 40. The wearer may select a particulardevice to be tested by selecting one of the listed devices in anydesired manner. Preferably, the wearer speaks commands into themicrophone, such as UP, DOWN, LEFT, RIGHT, ENTER, etc. which arerecognized and provided to the controller 54 and are used to move acursor (which may be a highlighted area) or to select items displayed ona Windows screen on the HUD 40. Of course, the wearer may also select adevice using the twiddler 46 or other keyboard device, by using themicrophone to enter the name or tag associated with a device, or usingthe video camera 38 to automatically identify a device as described withrespect to the routine 100 of FIG. 4.

A block 154 waits for the wearer to select a device and, after a deviceis selected or otherwise chosen by the wearer, a block 156 displays, viathe HUD 40, a list of communication channels associated with theselected device. An example of such a display using a Windows-typedisplay screen is illustrated in FIG. 7 and includes a set of 11communication channels for the device CTLR1 (controller 1) with thefirst channel CTLR1CO2CHO1 being highlighted. Of course, the list of I/Oor other communication channels may be displayed in any other manner andis not limited to that of FIG. 7.

Referring again to FIG. 6, a block 158 waits for the wearer to select acommunication channel to be checked. The wearer may select a particularchannel displayed in, for example, the screen of FIG. 7 using simplevoice commands such as BACK and NEXT to move the cursor to a differentchannel and ENTER to select that channel. Thus, to select the thirdcommunication channel (CTLR1C02CH03) when viewing the display screen ofFIG. 7, the wearer may simply say NEXT twice to highlight the channelCTLR1C02CH03 and then say ENTER to select that channel. While othervoice commands can be used, it is preferable to limit the set of voicecommands to simple words that can be recognized more easily by the voicerecognition unit 56. Also, while the display screen of FIG. 7 may bemanipulated using other input devices, such as the twiddler 46, it ispreferable to enable the wearer to manipulate the screen and select orenter data on the screen using voice signals or using other hands-freeinput devices which allow the wearer to use both of his or her hands forother activities.

After a user has selected a particular communication channel to check, ablock 160 displays a further screen on the HUD 40 which indicatesprocess information corresponding to the selected channel. An example ofsuch a screen is illustrated in FIG. 8 for the selected channel ofCTLR1C02CH01. To create the screen of FIG. 8, the block 160 obtains thecurrent process value of the selected communication channel from thehost system via the transceiver 36 and displays the current value ofthat channel (in this case “0”) along with an indication of the qualityof the signal (in this case “good”). The block 160 also provides an areafor the user to enter a new process value for the channel and indicatesthe type of signal on that channel, that is, whether the channel is ananalog channel or a digital channel, and the valid ranges of thatsignal. The information displayed on the screen is either stored in thememory 52 of the wearable computer system 30 or is obtained from thehost computer 14 which either stores that information in a memory orobtains the information from a device. In the illustrated example ofFIG. 8, the channel CTLR1C02CH01 is a digital channel currently set tothe value of zero. FIG. 9 illustrates a similar screen displayed on theHUD 40 for the channel CTLR1C06CH01 which is an analog channel having avalid range of 0-100 and which has a current value of 90.

When viewing the screen of FIG. 8 or 9, the user can manually measurethe value on the selected channel using, for example, a hand-heldvoltmeter or any other device. If the measured value is the same as thevalue listed in the current value field of the screen, then the wearercan continue by entering a new value in the new value field. Referringagain to FIG. 6, a block 162 waits for the wearer to enter a new processvalue, preferably using voice commands in the form of numbers and othersimple commands such as ENTER, BACK and NEXT, so that the wearer doesnot have to remove his or her hands from the metering device. A newvalue of 98.5 is being entered into the new value field of the screendisplay of FIG. 9. Upon receiving a new value, a block 164 sends thatnew value to the host system which then changes the selected channel tothe new value and, after verifying that the selected channel has beenchanged to the new value, sends the new value to the wearable computersystem 30 as the current value of the selected channel. A block 166 thenrefreshes the screen display on the HUD 40 to indicate that the currentvalue has been changed to the previously entered new value and clearsthe new value field to enable the wearer to enter a different new value.At this time, the wearer can measure the signal on the selected channelusing the hand-held meter to see if the signal has changed to theentered new value. If so, then the communication channel is most likelycorrectly connected and operating within the process control system. Ifnot, then a problem exists which must be identified and corrected. Ofcourse, the wearer may make further changes to the communication channelvalue and measure those changes, or may scroll back to the channel ordevice selection screens to select a different channel or device to bechecked.

Using the system described above, a single person may verify the properconnection and operation of different communication channels within aprocess control environment without needing to talk to and coordinatewith an operator located at a host station and without needing to carryaround a hand-held radio which gets in the way of the measurements andother activities being performed in the field.

In another embodiment, the wearable computer system 30 can be used tostore and automatically retrieve information pertaining to any device orobject within a process control environment, including devices that havedevice tags or other recognizable device features and objects such aswalkways, trash cans, buildings, etc. that do not typically have devicetags associated therewith. Using the wearable computer system 30 in thismanner, a wearer can walk around a plant or other process controlenvironment and record voice messages (or other information or data)pertaining to devices or objects within the plant for future retrievaleither by that wearer or by another person. Likewise, upon seeing adevice or other object, the wearer can determine (by looking at thedisplay on the HUD 40) if any voice messages have been previouslycreated for that device and can retrieve such previously created voicemessages.

In one embodiment, a software routine for implementing thisfunctionality (which may be stored in and executed by the processor orCPU 50 of the wearable computer 34) includes three basic routines, whichmay be separate routines or which may all be subparts of a singleroutine. The first routine identifies one or more devices within thefield of view of the wearer or as being of interest to the wearer. Thisroutine may, for example, accept voice inputs (from the microphone 44)in the form of device names, tags or other device identifiers toidentify devices that are currently of interest to the wearer.Similarly, this routine may display a list of devices to the wearer viathe HUD 40 and enable the wearer to select one of the displayed devicesusing, for example, voice commands or other inputs. Alternatively, thisroutine may automatically identify devices using the video imageprocessing routine described above with respect to FIG. 4, whichidentifies one or more visible device features. Instead of using devicefeatures, the automatic video processing routine may identify a devicebased on identifiers placed on or near the device for the specificpurpose of identifying the device (such as optical bar codes). On theother hand, transmitters may be placed on or near one or more devicesand these transmitters may send out a signal which is received by thewearable computer 34 and decoded by the routine to identify the one ormore devices. In one embodiment, a single transmitter may be used for aroom or other unit area and, upon receiving and decoding the transmittedsignal, the routine may access a memory (located, for example, in eitherthe wearable computer 34 or the host computer 14) which stores all ofthe devices within that room or unit area. A list of these devices maythen be provided to the wearer via the HUD 40. Similarly, devices thatdo not have tags or other automatically recognizable features may betied (in a database) to devices that have such automaticallyrecognizable features. Typically, devices in close proximity to oneanother will be tied together (associated with one another) in thedatabase. Thereafter, whenever one of the devices having anautomatically recognizable feature (a tagged device) is identified theroutine may consult the database to determine other non-tagged devicesthat are near to, or that are otherwise associated with the taggeddevice and display a list of all of these devices to the wearer via theHUD 40. Of course, other methods of identifying devices can be used aswell.

When one or more devices have been identified and, for example,displayed to the wearer via the HUD 40, a second routine enables thewearer to store a voice message to be associated with one of theidentified devices. The wearer may select one of the identified devices(using, for example, voice commands or any other type of input) andthen, when prompted via the HUD 40, speak into the microphone 44 tocreate a voice message. The second routine then stores the voice messagein a memory as being associated with the identified/selected device.This memory may be the memory 52 on the wearable computer 34 or,preferably, may be a memory somewhere within the host system such as inthe host computer 14. When stored on the host computer 14, the voicemessage is available to more than one wearable computer.

A third routine determines if any previously stored voice messages existfor any of the devices identified by the first routine and, if so,displays in indication, such as an icon, on the HUD 40 to tell thewearer that a previously stored message exists for that identifieddevice. When the wearer selects the icon using, for example, voicecommands, the third routine retrieves the previously stored voicemessage from the memory and plays it to the wearer via the speaker 42.

Using this data storage/retrieval unit, whenever a wearer (or anoperator of the host system 14) identifies a device, either manually orautomatically, the wearer (or the operator) can record a voice messageto be associated with that device and can, likewise, retrieve and hearpreviously stored voice messages associated with that device. In thismanner, a wearer (or operator) may make notes or leave messages about adevice or other object within the process control system which can laterbe retrieved by the same or a different person. Such a message may, forexample, inform the next person that repair is ongoing on the device, orthat calibration of the device needs to be performed, or may be anyother desired message pertaining to the device or object. In one simpleexample, a wearer may walk down a walkway within the process controlenvironment and notice that the walkway needs to be repainted orrepaired. (The walkway nay be identified automatically based on the roomthat the user is in, based on the proximity of the walkway to otherdevices that can be automatically identified using device features,based on specific codes or other features placed on the walkway toenable automatic identification, based on user generated input of anykind including voice input and hand operated device input, or in anyother manner.) The wearer may select the walkway on the HUD 40 and thenmake a voice message indicating the repair to be made to the walkway.Thereafter, whenever the walkway is recognized as being of interest oras being viewed by a wearer of a wearable computer (or an operator atthe host computer 14), the voice message is automatically made availableto that wearer (or operator) and is indicated as being available by anicon (which may also be a text message) associated with that walkway onthe HUD 40. In this manner, new information may be created and stored asassociated with any device or object within a process controlenvironment and this information may be later provided to a user in thesame manner and or at the same time that other, more standardinformation (such as help information) is made available to a user.

The routines described herein may, of course, be implemented in astandard multi-purpose CPU or on specifically designed hardware orfirmware as desired. When implemented in software, the software may bestored in any computer readable memory such as on a magnetic disk, alaser disk, or other storage medium, in a RAM or ROM of a computer orprocessor, etc. Likewise, this software may be delivered to a user or adevice (such as the wearable computer) via any known or desired deliverymethod including, for example, on a computer readable disk or othertransportable computer storage mechanism or over a communication channelsuch as a telephone line, the internet, etc. (which is viewed as beingthe same as or interchangeable with providing such software via atransportable storage medium).

While the present invention has been described with reference tospecific examples, which are intended to be illustrative only and not tobe limiting of the invention, it will be apparent to those of ordinaryskill in the art that changes, additions and/or deletions may be made tothe disclosed embodiments without departing from the spirit and scope ofthe invention.

What is claimed is:
 1. A wearable computer for use in a processenvironment having a process control system, comprising: a processingunit; a computer readable memory coupled to the processing unit; adisplay; an input device that provides an input signal to the processingunit; and one or more software routines stored in the computer readablememory and executable on the processing unit to process the input signaland provide process information pertaining to the process control systemvia the display based on the input signal; wherein the input device is amicrophone, the input signal is a speech signal and the one or moresoftware routines includes a speech recognition routine that processesthe speech signal to develop a user input.
 2. The wearable computer ofclaim 1, wherein the process information is diagnostic informationrelated to a device.
 3. The wearable computer of claim 1, wherein theprocess information is help information related to a device.
 4. Thewearable computer of claim 1, further including a remote communicationdevice that communicates with the process control system and wherein theprocess information is a process value obtained from a device by theprocess control system and sent to the wearable computer via the remotecommunication device.
 5. The wearable computer of claim 4, wherein theremote communication device is a wireless ethernet transceiver.
 6. Thewearable computer of claim 1, further including an imaging input devicethat produces an image frame and including an optical characterrecognition unit that performs optical character recognition on theimage frame.
 7. The wearable computer of claim 6, wherein the imagingdevice is a video camera that produces a multi-frame video signal andthe wearable computer further includes a frame grabber that grabs theimage frame from the multi-frame video signal and provides the imageframe to the optical character recognition routine.
 8. The wearablecomputer of claim 1, wherein the one or more software routines uses theuser input to identify a device.
 9. The wearable computer of claim 8,wherein the one or more software routines processes the user input todetermine a device tag.
 10. The wearable computer of claim 9, whereinthe process information is help information related to a deviceassociated with the determined device tag.
 11. The wearable computer ofclaim 9, further including a remote communication device thatcommunicates with the process control system and wherein the processinformation is a process value obtained by the process control systemfrom a device associated with the device tag and sent to the wearablecomputer via the remote communication device.
 12. The wearable computerof claim 1, wherein the display is a heads up display.
 13. The wearablecomputer of claim 1, wherein the speech recognition routine processesthe speech signal to develop the user input in the form of a command.14. A wearable computer for use in a process environment having aprocess control system, comprising: a processing unit; a computerreadable memory coupled to the processing unit; a display; a routinestored in the computer readable memory and run on the processing unitthat produces an image for display on the display; a microphone thatproduces a speech signal; and a voice recognition unit that processesthe speech signal to identify a command, wherein the routine causeschanges to be made in the image displayed on the display based on theidentified command.
 15. The wearable computer of claim 14, wherein thevoice recognition unit compares the speech signal to a set of storedrecognized commands to identify the command and wherein the set ofstored recognized commands are related to moving a cursor on the imagedisplayed on the display.
 16. The wearable computer of claim 15, whereinthe set of stored recognized commands comprises one of a left movementcommand, a right movement command, an up movement command and a downmovement command.
 17. The wearable computer of claim 14, wherein thevoice recognition unit compares the speech signal to a set of storedrecognized commands to identify the command and wherein the set ofstored recognized commands are related to entering alpha-numeric data ina field within the image displayed on the display.
 18. The wearablecomputer of claim 14, wherein the routine displays the image as having alist of devices for selection and the voice recognition unit identifiesone of the list of devices based on the speech signal.
 19. The wearablecomputer of claim 14, wherein the routine displays an image having alist of channels for selection and the voice recognition unit identifiesone of the list of channels based on the speech signal.
 20. The wearablecomputer of claim 14, wherein the routine displays the image as having aprocess value and a field for changing the process value.
 21. Thewearable computer of claim 14, wherein the display is a heads updisplay.
 22. A wearable computer system for use in altering or testing aprocess control system, comprising: a processing unit; a computerreadable memory; an input device that develops an input signal in theform of a speech signal; a remote communication device that communicateswith the process control system; a voice recognition unit that processesthe speech signal to decode the speech signal; a software routineexecutable on the processing unit to use the decoded speech signal todevelop a change signal indicating a change to be made in a parameterwithin the process control system and to communicate the change signalto the process control system via the remote communication device tothereby cause a change to be made to the process control system.
 23. Thewearable computer of claim 22, further including a display and whereinthe software routine communicates with the process control system toobtain the actual value of a process signal and displays the actualvalue of the process signal via the display.
 24. The wearable computerof claim 22, wherein the input device includes a microphone.
 25. Thewearable computer of claim 22, further including a display that displaysan image and wherein the software routine produces a screen on thedisplay having a list of communication channels therein and enables theuser to select one of the communication channels using the input device.26. The wearable computer of claim 25, wherein the software routinedisplays a type of process signal on a selected communication channelvia the display.
 27. The wearable computer of claim 25, wherein thesoftware routine displays a valid range of a process signal on aselected communication channel via the display.
 28. The wearablecomputer of claim 25, wherein the software routine enables a user toenter the change signal for the process signal in a field on the displayvia the input device.
 29. A process control communication unit for usein a wearable computer having a processor, a microphone that develops aninput signal in the form of a speech signal, a display and a remotecommunication device that communicates with a process control system,the process control communication unit comprising: a memory; a voicerecognition unit that decodes the speech signal to develop a user inputinstruction; and a software routine stored on the memory and executableon the processor of the wearable computer to process the user inputinstruction to develop a change signal indicating a change to be made ina process signal within the process control system and to communicatethe change signal to the process control system via the remotecommunication device to thereby cause the change to be made to theprocess signal.
 30. The process control communication unit of claim 29,wherein the change signal indicates a change in a communication signaland causes the communication signal to be changed from a first value toa second value.
 31. The process control communication unit of claim 29,wherein the software routine communicates with the process controlsystem to obtain the actual value of the process signal and displays theactual value of the process signal via the display.
 32. The processcontrol communication unit of claim 29, wherein the software routinedisplays a set of different process control signals for selection viathe display.
 33. The process control communication unit of claim 29,wherein the software routine produces a screen on the display having alist of communication channels therein and enables a user to select oneof the communication channels using the microphone.
 34. The processcontrol communication unit of claim 29, wherein the software routineenables a user to enter the change signal for the process signal in afield on the display using the microphone.
 35. A wearable computercomprising: a processor; a microphone that produces a speech signal; adisplay; a computer readable memory; a voice recognition unit thatprocesses speech signal to produce an input signal; a first softwareroutine stored on the computer readable memory and executable on theprocessor to identify a process control device based on the inputsignal; a second software routine stored on the computer readable memoryand executable on the processor to provide an indication via the displaythat a previously stored information signal is available for theidentified process control device when the previously stored informationsignal exists for the identified process control device and thatprovides the previously stored information signal for the identifiedprocess control device in response to a second user input selecting thepreviously stored information signal for the identified process controldevice for retrieval.
 36. The wearable computer of claim 35, furtherincluding a remote communication device that communicates with a processcontrol system coupled to the identified process control device and afurther memory that stores the previously stored information signalwithin the process control system, and further including a thirdsoftware routine that communicates with the further memory via theremote communication device.
 37. The wearable computer of claim 36,wherein the second software routine displays an icon via the display asthe indication.
 38. The wearable computer of claim 37, wherein thesecond user input signal is a voice signal, the voice recognition unitprocesses the voice signal to identify a user command to select the iconand the second software routine replays the previously stored voicesignal for the identified process control device when the icon isselected.
 39. The wearable computer of claim 35, wherein the previouslystored information signal is a voice signal.
 40. The wearable computerof claim 35, further including a third software routine stored on thecomputer readable memory and executable on the processor to receive avoice signal from the microphone and store the received voice signal asbeing linked to the identified process control device in a furthermemory in response to a first user input to store the received voicesignal.